Pakistan Arrests 21 in ‘Heartsender’ Malware Service

Authorities in Pakistan have arrested 21 individuals accused of operating “Heartsender,” a once popular spam and malware dissemination service that operated for more than a decade. The main clientele for HeartSender were organized crime groups that tried to trick victim companies into making payments to a third party, and its alleged proprietors were publicly identified by KrebsOnSecurity in 2021 after they inadvertently infected their computers with malware.

A report from the Pakistani media outlet Dawn states that authorities there arrested 21 people alleged to have operated Heartsender, a spam delivery service whose homepage openly advertised phishing kits targeting users of various Internet companies, including Microsoft 365, Yahoo, AOL, Intuit, iCloud and ID.me. Pakistan’s National Cyber Crime Investigation Agency (NCCIA) reportedly conducted raids in Lahore’s Bahria Town and Multan on May 15 and 16.

The NCCIA told reporters the group’s tools were connected to more than $50m in losses in the United States alone, with European authorities investigating 63 additional cases.

“This wasn’t just a scam operation – it was essentially a cybercrime university that empowered fraudsters globally,” NCCIA Director Abdul Ghaffar said at a press briefing.

In January 2025, the FBI and the Dutch Police seized the technical infrastructure for the cybercrime service, which was marketed under the brands Heartsender, Fudpage and Fudtools (and many other “fud” variations). The “fud” bit stands for “Fully Un-Detectable,” and it refers to cybercrime resources that will evade detection by security tools like antivirus software or anti-spam appliances.

The FBI says transnational organized crime groups that purchased these services primarily used them to run business email compromise (BEC) schemes, wherein the cybercrime actors tricked victim companies into making payments to a third party.

Dawn reported that those arrested included Rameez Shahzad, the alleged ringleader of the Heartsender cybercrime business, which most recently operated under the Pakistani front company WeCodeSolutions. Mr. Shahzad was named and pictured in a 2021 KrebsOnSecurity story about a series of remarkable operational security mistakes that exposed their identities and Facebook pages showing employees posing for group photos and socializing at work-related outings.

Prior to folding their operations behind WeCodeSolutions, Shahzad and others arrested this month operated as a web hosting group calling itself The Manipulaters. KrebsOnSecurity first wrote about The Manipulaters in May 2015, mainly because their ads at the time were blanketing a number of popular cybercrime forums, and because they were fairly open and brazen about what they were doing — even who they were in real life.

Sometime in 2019, The Manipulaters failed to renew their core domain name — manipulaters[.]com — the same one tied to so many of the company’s business operations. That domain was quickly scooped up by Scylla Intel, a cyber intelligence firm that specializes in connecting cybercriminals to their real-life identities. Soon after, Scylla started receiving large amounts of email correspondence intended for the group’s owners.

In 2024, DomainTools.com found the web-hosted version of Heartsender leaked an extraordinary amount of user information to unauthenticated users, including customer credentials and email records from Heartsender employees. DomainTools says the malware infections on Manipulaters PCs exposed “vast swaths of account-related data along with an outline of the group’s membership, operations, and position in the broader underground economy.”

Shahzad allegedly used the alias “Saim Raza,” an identity which has contacted KrebsOnSecurity multiple times over the past decade with demands to remove stories published about the group. The Saim Raza identity most recently contacted this author in November 2024, asserting they had quit the cybercrime industry and turned over a new leaf after a brush with the Pakistani police.

The arrested suspects include Rameez Shahzad, Muhammad Aslam (Rameez’s father), Atif Hussain, Muhammad Umar Irshad, Yasir Ali, Syed Saim Ali Shah, Muhammad Nowsherwan, Burhanul Haq, Adnan Munawar, Abdul Moiz, Hussnain Haider, Bilal Ahmad, Dilbar Hussain, Muhammad Adeel Akram, Awais Rasool, Usama Farooq, Usama Mehmood and Hamad Nawaz.